Support /join @publicgroup syntax

telegram/commands.go

@@ -61,7 +61,7 @@ var chatCommands = map[string]command{
 	"schedule":   command{"{online | 2006-01-02T15:04:05 | 15:04:05} message", "schedules a message either to timestamp or to whenever the user goes online"},
 	"forward":    command{"message_id target_chat", "forwards a message"},
 	"add":        command{"@username", "add @username to your chat list"},
-	"join":       command{"https://t.me/invite_link", "join to chat via invite link"},
+	"join":       command{"https://t.me/invite_link", "join to chat via invite link or @publicname"},
 	"group":      command{"title", "create groupchat «title» with current user"},
 	"supergroup": command{"title description", "create new supergroup «title» with «description»"},
 	"channel":    command{"title description", "create new channel «title» with «description»"},
@@ -623,18 +623,36 @@ func (c *Client) ProcessChatCommand(chatID int64, cmdline string) (string, bool)
 		}
 
 		c.subscribeToID(chat.Id, chat)
-	// join https://t.me/publichat
+	// join https://t.me/publichat or @publicchat
 	case "join":
 		if len(args) < 1 {
 			return notEnoughArguments, true
 		}
 
+		if strings.HasPrefix(args[0], "@") {
+			chat, err := c.client.SearchPublicChat(&client.SearchPublicChatRequest{
+				Username: args[0],
+			})
+			if err != nil {
+				return err.Error(), true
+			}
+			if chat == nil {
+				return "No error, but chat is nil", true
+			}
+			_, err = c.client.JoinChat(&client.JoinChatRequest{
+				ChatId: chat.Id,
+			})
+			if err != nil {
+				return err.Error(), true
+			}
+		} else {
 			_, err := c.client.JoinChatByInviteLink(&client.JoinChatByInviteLinkRequest{
 				InviteLink: args[0],
 			})
 			if err != nil {
 				return err.Error(), true
 			}
+		}
 	// create new supergroup
 	case "supergroup":
 		if len(args) < 1 {